Alkali metal anode/chalcogenide cathode reversible batteries having alkali metal polyaryl metallic compound electrolytes

Abstract

Reversible alkali metal anode/metal chalcogenide cathode cells, e.g. lithium batteries, are described having electrolyte compositions which consist essentially of (a) organic solvents selected from the group consisting of inertly substituted and unsubstituted ethers, esters, sulfones, organic sulfites, organic sulfates, organic nitrites and organic nitro compounds; and (b) electrolytically active alkali metal salts including polyaryl metallic alkali metal salts having the formula ZMRn wherein Z is an alkali metal, M is a metal selected from the group consisting of Zn, Cd, B, Al, Ga, In, Tl, Sn (stannous), P and As, the Rs are certain aryl radicals, and n is a numerical value equal to one plus the valence of the metal M. Rechargeable, high energy density electrochemical cells containing an anode having an alkali metal as its active material, a cathode having as its active material a transition metal chalcogenide, e.g. TiS2, and an electrolyte composition of the above-described type, are preferred.

What is claimed is: 
     
       1. In an electrochemical cell which contains an alkali metal anode, a metal chalcogenide cathode and a non-aqueous electrolyte, the improvement comprising: using as said electrolyte one which consists essentially of: (a) an organic solvent selected from the group consisting of inertly substituted and unsubstituted ethers, sulfones, organic sulfates, organic sulfites, organic nitro compounds and organic nitrites; and,   (b) electrolytically active alkali metal salts including an electrolytically active amount of a polyaryl metallic alkali metal salt having the formula:   ZMR.sub.n        wherein Z is an alkali metal, wherein M is a metal selected from the group consisting of Zn, Cd, B, Al, Ga, Sn (stannous), In, Tl, P and As, wherein R represents n number of radicals which may be the same or different and are inertly substituted or unsubstituted aryl radicals selected from the group consisting of aryl radicals having 6 to 50 carbon atoms, and wherein n is a numerical value equal to one plus the valence of the metal M.     
     
     
       2. The cell of claim 1 wherein in the electrolyte, Z is an alkali metal selected from the group consisting of lithium, sodium, and potassium, M is a metal selected from the group consisting of B, Al, P and As, and wherein the aryl radicals R may be the same or different and are inertly substituted or unsubstituted aryl radicals selected from the group consisting of phenyl, tolyl, biphenyl, and naphthyl radicals. 
     
     
       3. The cell of claim 2 wherein the cell is a secondary cell and the organic solvent is an ether. 
     
     
       4. The cell of claim 3 wherein, in the electrolyte, Z is lithium and wherein M is boron. 
     
     
       5. The cell of claim 4 wherein said organic solvent is one or more ethers and wherein all of the aryl radicals R are phenyl radicals. 
     
     
       6. The cell of claim 1 wherein the cathode comprises a solid metal dichalcogenide. 
     
     
       7. The cell of claim 6 wherein in the electrolyte, Z is an alkali metal selected from the group consisting of lithium, sodium, and potassium, M is a metal selected from the group consisting of B, Al, P and As, and wherein the aryl radicals R may be the same or different and are inertly substituted or unsubstituted aryl radicals selected from the group consisting of phenyl, tolyl, biphenyl, and naphthyl radicals. 
     
     
       8. The cell of claim 7 wherein the cell is a secondary cell and the organic solvent is an ether. 
     
     
       9. The cell of claim 8 wherein, in the electrolyte, Z is lithium and wherein M is boron. 
     
     
       10. The cell of claim 9 wherein said organic solvent is one or more ethers and wherein all of the aryl radicals R are phenyl radicals. 
     
     
       11. In an electrochemical cell which includes an anode having at least one alkali metal as its active material, a cathode having a transition metal chalcogenide as the cathode-active material and an electrolyte composition, the improvement wherein said electrolyte composition consists essentially of: (a) an organic solvent selected from the group consisting of inertly substituted and unsubstituted ethers, sulfones, organic sulfates, organic sulfites, organic nitro compounds and organic nitrites; and   (b) electrolytically active alkali metal salts including an electrolytically active amount of a polyaryl metallic alkali metal salt having the formula:   ZMR.sub.n        wherein Z is an alkali metal, wherein M is a metal selected from the group consisting of Zn, Cd, B, Al, Ga, Sn (stannous), In, Tl, P and As, wherein R represents n number of radicals which may be the same or different and are inertly substituted or unsubstituted aryl radicals selected from the group consisting of aryl radicals having 6 to 50 carbon atoms, and wherein n is a numerical value equal to one plus the valence of the metal M.   
     
     
       12. The electrochemical cell of claim 11 wherein, in the electrolyte, Z is an alkali metal selected from the group consisting of lithium, sodium, and potassium, M is a metal selected from the group consisting of B, Al, P and As, and wherein the aryl radicals R may be the same or different and are inertly substituted or unsubstituted aryl radicals selected from the group consisting of phenyl, tolyl, biphenyl and naphthyl radicals. 
     
     
       13. The electrochemical cell of claim 12 wherein the anode-active material is lithium or alloys thereof, wherein the cathode-active material is titanium disulfide, and wherein, in the electrolyte, Z is lithium. 
     
     
       14. The electrochemical cell of claim 13 wherein said organic solvent is one or more ethers. 
     
     
       15. The electrochemical cell of claim 13 wherein, in the electrolyte, Z is lithium, wherein M is boron. 
     
     
       16. The electrochemical cell of claim 15 wherein said organic solvent is one or more ethers and wherein all of the aryl radicals R are all phenyl radicals. 
     
     
       17. The electrochemical cell of claim 16 wherein the solvent contains dioxolane. 
     
     
       18. The electrochemical cell of claim 17 wherein the concentration of the organometallic alkali metal salt in said solvent is about 0.1 to about 5 moles/liter. 
     
     
       19. The electrochemical cell of claim 18 wherein the concentration of the organometallic alkali metal salt in said solvent is about 0.5 to About 3 moles/liter.